feat: init function

Author: 崔竞宁

.gitignore

@@ -13,3 +13,5 @@
 
 # Dependency directories (remove the comment below to include it)
 # vendor/
+
+.DS_Store

README.md

@@ -1,2 +1,30 @@
 # go-querystring-parser
 A golang querystring parser
+
+## Usage
+
+```go
+import (
+    querystring "github.com/bytedance/go-querystring-parser"
+)
+```
+
+Then use:
+
+```go
+query := "message: test\\ value AND datetime: [\"2020-01-01T00:00:00\" TO \"2020-12-31T00:00:00\"]"
+ast, err := querystring.Parse(query)
+if err != nil {
+    // error handling
+}
+
+// do something with ast
+```
+
+## For Developers
+
+After edit querystring.y, gen code via run:
+
+```shell
+go generate
+```

condition.go

@@ -0,0 +1,165 @@
+package querystring
+
+import (
+	"strings"
+	"time"
+)
+
+// Condition .
+type Condition interface {
+}
+
+// AndCondition .
+type AndCondition struct {
+	Left  Condition
+	Right Condition
+}
+
+// NewAndCondition .
+func NewAndCondition(left, right Condition) *AndCondition {
+	return &AndCondition{Left: left, Right: right}
+}
+
+// OrCondition .
+type OrCondition struct {
+	Left  Condition
+	Right Condition
+}
+
+// NewOrCondition .
+func NewOrCondition(left, right Condition) *OrCondition {
+	return &OrCondition{Left: left, Right: right}
+}
+
+// NotCondition .
+type NotCondition struct {
+	Condition Condition
+}
+
+// NewNotCondition .
+func NewNotCondition(q Condition) *NotCondition {
+	return &NotCondition{Condition: q}
+}
+
+// FieldableCondition .
+type FieldableCondition interface {
+	SetField(field string)
+}
+
+// MatchCondition .
+type MatchCondition struct {
+	Field string
+	Value string
+}
+
+// NewMatchCondition .
+func NewMatchCondition(s string) *MatchCondition {
+	return &MatchCondition{
+		Value: s,
+	}
+}
+
+// SetField .
+func (q *MatchCondition) SetField(field string) {
+	q.Field = field
+}
+
+// RegexpCondition .
+type RegexpCondition struct {
+	Field string
+	Value string
+}
+
+// NewRegexpCondition .
+func NewRegexpCondition(s string) *RegexpCondition {
+	return &RegexpCondition{
+		Value: s,
+	}
+}
+
+// SetField .
+func (q *RegexpCondition) SetField(field string) {
+	q.Field = field
+}
+
+// WildcardCondition .
+type WildcardCondition struct {
+	Field string
+	Value string
+}
+
+// NewWildcardCondition .
+func NewWildcardCondition(s string) *WildcardCondition {
+	return &WildcardCondition{
+		Value: s,
+	}
+}
+
+// SetField .
+func (q *WildcardCondition) SetField(field string) {
+	q.Field = field
+}
+
+// NumberRangeCondition .
+type NumberRangeCondition struct {
+	Field        string
+	Start        *string
+	End          *string
+	IncludeStart bool
+	IncludeEnd   bool
+}
+
+// NewNumberRangeCondition .
+func NewNumberRangeCondition(start, end *string, includeStart, includeEnd bool) *NumberRangeCondition {
+	return &NumberRangeCondition{
+		Start:        start,
+		End:          end,
+		IncludeStart: includeStart,
+		IncludeEnd:   includeEnd,
+	}
+}
+
+// SetField .
+func (q *NumberRangeCondition) SetField(field string) {
+	q.Field = field
+}
+
+// TimeRangeCondition .
+type TimeRangeCondition struct {
+	Field        string
+	Start        *string
+	End          *string
+	IncludeStart bool
+	IncludeEnd   bool
+}
+
+// NewTimeRangeCondition .
+func NewTimeRangeCondition(start, end *string, includeStart, includeEnd bool) *TimeRangeCondition {
+	return &TimeRangeCondition{
+		Start:        start,
+		End:          end,
+		IncludeStart: includeStart,
+		IncludeEnd:   includeEnd,
+	}
+}
+
+// SetField .
+func (q *TimeRangeCondition) SetField(field string) {
+	q.Field = field
+}
+
+func queryTimeFromString(t string) (time.Time, error) {
+	return time.Parse(time.RFC3339, t)
+}
+
+func newStringCondition(str string) FieldableCondition {
+	if strings.HasPrefix(str, "/") && strings.HasSuffix(str, "/") {
+		return NewRegexpCondition(str[1 : len(str)-1])
+	}
+
+	if strings.ContainsAny(str, "*?") {
+		return NewWildcardCondition(str)
+	}
+
+	return NewMatchCondition(str)
+}